Algal growth inhibition by river water pollutants in the agricultural area around Lake Biwa, Japan

• Published in: Environmental pollution (1987) Vol. 117; no. 3; pp. 411 - 419
• Main Authors: Okamura, Hideo, Piao, Mingyu, Aoyama, Isao, Sudo, Miki, Okubo, Takuya, Nakamura, Masahisa
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.01.2002; Elsevier
• Subjects: Agriculture - methods; Agronomy. Soil science and plant productions; Algal bioassay; Animal, plant and microbial ecology; Animals; Applied ecology; Araceae - drug effects; Biological and medical sciences; Biological Assay; Chlorophyta - drug effects; Chlorophyta - growth & development; Daphnia - drug effects; Ecology; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on plants and fungi; Fresh Water - analysis; Freshwater; Fundamental and applied biological sciences. Psychology; Herbicide; Japan; Lactuca - drug effects; Lake Biwa; Pesticides - analysis; Pesticides - toxicity; Runoff; Seasons; Simetryn; Soil and water pollution; Soil science; Water Movements; Water Pollutants, Chemical - analysis; Water Pollutants, Chemical - toxicity; Water Pollution, Chemical - analysis; Asia; Honshu; Japan; Japan, Honshu, Shiga Prefect., Biwa L; Algal bioassay; Lake Biwa; Simetryn; Runoff; Herbicide; Growth; Algae; POLLUTION BY AGRICULTURE; Experimental study; Lacustrine environment; Freshwater environment; Pollutant; Analysis method; Regional study; Lakes; Rural area; Environment; Water pollution; Pollutant effect; Inhibition; River water; Thallophyta
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/S0269-7491(01)00196-8

Low-cost bioassays can be used to prioritize samples for pesticide analysis. An ecotoxicological study of river water discharged from the agricultural area around Lake Biwa was performed by using algal bioassays to guide chemical analysis. Water samples were collected once a week, at least, for 1 year starting in April 1997 and continuing until April 1998. The toxicities of the dissolved and particulate-adsorbed extracts of water samples were evaluated by the algal growth inhibition test and concentrations of individual pesticides were determined. Most of the river water that was collected during the periods when pesticides were applied to the paddy fields caused algal growth inhibition. Some extracts were found to contain herbicides (molinate, mefenacet, simetryn, or esprocarb) as major compounds. According to chemical assay and bioassay, simetryn was identified as the most toxic compound that caused algal growth inhibition.